12h 14m 6s The degree separator may be a degree symbol (\xBA) in addition to a 'd' or 'D'.

Returns

the angle in radians. Latitude: North are positive, South are negative. Longitude: East is positive, West is negative. Note: if there is a N, S, E or W suffix, any leading + or - characters are ignored.

double StelUtils::getDeltaTByAstronomicalEphemeris

(

const double

jDay

)

Get Delta-T estimation for a given date.

Implementation of algorithm by Astronomical Ephemeris (1960) for DeltaT computation. Sources: Spencer Jones, H., "The Rotation of the Earth, and the Secular Accelerations of the Sun, Moon and Planets", Monthly Notices of the Royal Astronomical Society, 99 (1939), 541-558 http://adsabs.harvard.edu/abs/1939MNRAS..99..541S or Explanatory Supplement to the Astr. Ephemeris, 1961, p.87. Also used by Mucke&Meeus, Canon of Solar Eclipses, Vienna 1983.

Implementation of algorithm by Clemence (1948) for DeltaT computation, outdated but may be useful for science-historical purposes. Source: On the system of astronomical constants. Clemence, G. M. Astronomical Journal, Vol. 53, p. 169 1948AJ.....53..169C [http://adsabs.harvard.edu/abs/1948AJ.....53..169C]

Parameters

jDay

the date and time expressed as a julian day

Returns

Delta-T in seconds

double StelUtils::getDeltaTByEspenak

(

const double

jDay

)

Get Delta-T estimation for a given date.

Implementation of algorithm by Espenak (1987, 1989) for DeltaT computation. This relation should not be used before around 1950 or after around 2100 (Espenak, pers. comm.).

Parameters

jDay

the date and time expressed as a julian day

Returns

Delta-T in seconds

double StelUtils::getDeltaTByEspenakMeeus

(

const double

jDay

)

Get Delta-T estimation for a given date.

Note that this method is valid for the year range: -1999 to +3000, outside of which "0" will be returned. Implementation of algorithm by Espenak & Meeus (2006) for DeltaT computation

Parameters

jDay

the date and time expressed as a julian day

Returns

Delta-T in seconds

double StelUtils::getDeltaTByIAU

(

const double

jDay

)

Get Delta-T estimation for a given date.

Implementation of algorithm by IAU (1952) for DeltaT computation, outdated but may be useful for science-historical purposes. Source: Spencer Jones, H., "The Rotation of the Earth, and the Secular Accelerations of the Sun, Moon and Planets", Monthly Notices of the Royal Astronomical Society, 99 (1939), 541-558 http://adsabs.harvard.edu/abs/1939MNRAS..99..541S

Implementation of algorithm by Montenbruck & Pfleger (2000) for DeltaT computation, a data fit through the table of values found in Meeus, Astronomical algorithms (1991). Book "Astronomy on the Personal Computer" by O. Montenbruck & T. Pfleger (4th ed., 2000)

Implementation of algorithm by Reingold & Dershowitz (1997, 2001, 2002, 2007) for DeltaT computation. This is again mostly a data fit based on the table in Meeus, Astronomical Algorithms (1991). This is the version given in the 3rd edition (2007) which added the fit for 1700..1799 omitted from previous editions.

This is implemented in platform-specific ways to be as precise as possible, but there is a fallback for other platforms that might not be precise at all. This is currently used e.g. to measure FPS, but it should never be used for critical functionality.

int StelUtils::smallestPowerOfTwoGreaterOrEqualTo

(

const int

value

)

Return the first power of two greater or equal to the given value.

QSize StelUtils::smallestPowerOfTwoSizeGreaterOrEqualTo

(

const QSize

base

)

Return the smallest size with power-of two dimensions at least as large as given size.